This invention relates to data recording and in particular to novel improved multi-disk arrangements of data records adapted for automatic partitioning.
Workers in the art of generating and using recording media are aware of the various forms it takes; in the case of digital recording these forms have historically comprised drums, disks and tape in various configurations. Each medium has its own advantages and shortcomings depending upon the application. As mentioned in U.S. Pat. No. 4,086,640, magnetic disks have well known advantages, and in the form of "flexible disks" can serve as a "unit record" medium that is compact, light, and is readily transported, stored and handled, interchangably with other like disks. Flexible (or "floppy) disks are now widely used in the data processing arts.
Workers recognize that costs may be reduced in many cases by replacing a rigid magnetic recording disk with a "floppy" disk. Floppy disks can be fashioned from well-known polyester sheet material (e.g., the familiar polyethylene terephthalate used for magnetic tape) with a magnetic coating thereon--this plastic being simply cut into the shape of a circular disk with a central mounting hole to accommodate the familiar drive-spindle. Such a "prior art" floppy disk is well known to workers and is shown in FIG. 1; a conventional envelope, or jacket, therefor is illustrated in FIG. 2.
The present invention is directed toward improving the design of such flexible magnetic disks as adapted for collection in a "floppy pack" such that automatic partition means may be employed to split the pack and expose any selected disk surface. That is, an improved "floppy disk pack" according to the invention is particularly adapted for such automatic partitioning--using surprisingly simple means and methods as described hereinafter.
Prior efforts with flexible disks:
Workers are familiar with prior approaches to the design and manufacture of floppy disks and to related equipment for handling them. Several are described in U.S. Pat. No. 4,086,640.
Workers are aware that for many applications of floppy disk pack applications, it is of paramount importance to minimize disk cost while yet maintaining accurate, reliable operation. Thus, it is often desirable to fabricate all floppy disks in a pack by a single common pressing operation, with all disks identical--yet still render the disks uniquely "selectable" when collected into a pack. The invention teaches this, and other techniques, using utterly simple expedients. For example, with the invention an identical set of disks may be stacked with each disk in turn merely rotated by a prescribed angle relative to its predecessor and thereby produce a floppy pack affording the "plunger-partition" characteristics described in U.S. Pat. No. 4,086,640. Using a prescribed pattern of index holes such a pack will exhibit the desired "reference axes" from which "select angles" may be determined.
According to a further feature, such a "common perforation" mode of disk construction and pack arrangement may also be adapted for "dual-side recording" with the (common) partition and indexing hole pattern arranged to allow "flip-side" operation. Workers who appreciate the remarkable character of "floppy packs" in general will best appreciate these features and their surprising effectiveness despite the surprising simplicity of the techniques and the unexpected versatility of such "common perforation" disks. For instance, it was quite unexpected that with the disk design so-simplified it could nonetheless afford a wide latitude in selecting the number and position of "partition sites".
The present invention is directed toward providing improved multi-disk record units (disk packs) which are better adapted to meet the foregoing problems annd objectives in a manner satisfying minimum-cost objectives. The invention maintains the convenience of packaging a number of floppy disks in an "end-wise" partitionable file, while prescribing improved simplified techniques for fabricating the disks and pack. This file may take the form of a few floppy disks bound together in a portable pack (e.g., and mechanically partitioned) or many floppies permanently affixed upon a hollow spindle (e.g., and pneumatically partitioned from within the stack's axial region).
The foregoing and other features, objects and advantages according to the present invention will be more fully appreciated and become more apparent upon consideration of the following description of preferred embodiments, taken in conjunction with the attached drawings, wherein like reference indicia denote like elements.